fix: replace unguarded crypto.randomUUID() with safe generateUUID() utility

stores/calendar-store.ts

@@ -6,6 +6,7 @@ import { debug } from '@/lib/debug';
 import { normalizeAllDayDuration } from '@/lib/calendar-utils';
 import { sanitizeOutgoingCalendarEventData } from '@/lib/calendar-event-normalization';
 import { expandRecurringEvents } from '@/lib/recurrence-expansion';
+import { generateUUID } from '@/lib/utils';
 
 export type CalendarViewMode = 'month' | 'week' | 'day' | 'agenda' | 'tasks';
 
@@ -722,9 +723,7 @@ export const useCalendarStore = create<CalendarStore>()(
           if (!calendar) throw new Error('Failed to create calendar');
 
           const subscription: ICalSubscription = {
-            id: typeof crypto !== 'undefined' && typeof crypto.randomUUID === 'function'
-              ? crypto.randomUUID()
-              : `${Date.now()}-${Math.random().toString(36).slice(2, 11)}`,
+            id: generateUUID(),
             url,
             calendarId: calendar.id,
             name,

stores/contact-store.ts

@@ -2,6 +2,7 @@ import { create } from 'zustand';
 import { persist } from 'zustand/middleware';
 import type { ContactCard, AddressBook, ContactName } from '@/lib/jmap/types';
 import type { IJMAPClient } from '@/lib/jmap/client-interface';
+import { generateUUID } from '@/lib/utils';
 
 export function getContactDisplayName(contact: ContactCard): string {
   if (contact.name?.components) {
@@ -378,7 +379,7 @@ export const useContactStore = create<ContactStore>()(
           set((state) => ({ contacts: [...state.contacts, created] }));
         } else {
           const localGroup: ContactCard = {
-            id: `local-${crypto.randomUUID()}`,
+            id: `local-${generateUUID()}`,
             addressBookIds: {},
             ...groupData,
           } as ContactCard;
@@ -617,7 +618,7 @@ export const useContactStore = create<ContactStore>()(
             } else {
               const localContact: ContactCard = {
                 ...contact,
-                id: `local-${crypto.randomUUID()}`,
+                id: `local-${generateUUID()}`,
               };
               set((state) => ({ contacts: [...state.contacts, localContact] }));
             }

stores/smime-store.ts

@@ -1,6 +1,7 @@
 import { create } from 'zustand';
 import { persist } from 'zustand/middleware';
 import type { SmimeKeyRecord, SmimePublicCert } from '@/lib/smime/types';
+import { generateUUID } from '@/lib/utils';
 import {
   saveKeyRecord,
   listKeyRecords,
@@ -287,7 +288,7 @@ export const useSmimeStore = create<SmimeStore>()(
           const email = info.emailAddresses[0] ?? '';
 
           const publicCert: SmimePublicCert = {
-            id: crypto.randomUUID(),
+            id: generateUUID(),
             accountId: get().currentAccountId ?? undefined,
             email: email.toLowerCase(),
             certificate: der,

stores/template-store.ts

@@ -6,6 +6,7 @@ import {
   importTemplates as importUtil,
   filterTemplates,
 } from '@/lib/template-utils';
+import { generateUUID } from '@/lib/utils';
 
 const MAX_RECENT = 5;
 
@@ -39,7 +40,7 @@ export const useTemplateStore = create<TemplateStore>()(
         const now = new Date().toISOString();
         const template: EmailTemplate = {
           ...data,
-          id: crypto.randomUUID(),
+          id: generateUUID(),
           createdAt: now,
           updatedAt: now,
         };
@@ -73,8 +74,9 @@ export const useTemplateStore = create<TemplateStore>()(
         const now = new Date().toISOString();
         const duplicate: EmailTemplate = {
           ...original,
-          id: crypto.randomUUID(),
+          id: generateUUID(),
           name: `${original.name} ${nameSuffix || '(copy)'}`,
+
           isFavorite: false,
           createdAt: now,
           updatedAt: now,